The present invention relates to a molded article which includes a hollow blow molded thermoplastic rigid member that is integrally attached to a rigid support, e.g., a metal plate. A thermoplastic parison precursor of the hollow rigid thermoplastic member is blow molded against the rigid support. Portions of the thermoplastic parison extend through perforations in the rigid support, thereby attaching the hollow thermoplastic rigid member to the rigid support. The present invention also relates to a process by which the molded article is prepared.
In applications involving the transportation of air, a plastic conduit is typically used, as is the case, for example, in some heating, ventilating and air conditioning (HVAC) systems. The plastic conduit may be self supporting. However, in those applications where additional structural and dimensional stability are required (e.g., in the automotive and aircraft industries), the plastic conduit is often connected to and supported by a separate support structure. In most automotive vehicles, a cross car beam spans and extends between the vehicle door pillars (commonly referred to as the A-pillars). The cross car beam, which is typically fabricated from metal, provides rigidity and structural support to the vehicle, e.g., relative to a lateral impact upon the vehicle. The cross car beam also typically provides support for and is attached to the interior instrument panel and the HVAC system of the vehicle.
Typically the plastic conduit and the support structure are separately fabricated, and then attached together in a separate step. The plastic conduit and support structure (e.g., a cross car beam in the form of a metal beam or tube) are typically attached together by means of, for example, fasteners, adhesives, straps and/or brackets. Such attachment methods typically involve a series of manufacturing steps, and the use of additional materials. e.g., rivets, bolts and adhesives. In the case of an automotive application, for example, the separately fabricated cross car beam and plastic conduit, when assembled together, can take up an undesirably large amount of space within the passenger compartment.
In the transportation industries, e.g., the automotive and aircraft industries, it is desirable to minimize the weight of the vehicle or aircraft in an effort towards maximizing fuel efficiency. The total weight of a vehicle or aircraft can be reduced by reducing the weight of its components. However, it is generally required that the strength and rigidity of a component not be compromised as the weight of the component is reduced. It is also desirable in the transportation industries to minimize the space occupied by various components that are incorporated into the vehicle or aircraft.
A need thus exists for the development of molded articles having a rigid support and a rigid thermoplastic hollow member attached thereto, that provide a combination of structural stability, reduced weight and compact (or space saving) design. A need also exists with regard to the development of new methods of preparing such molded articles in which the rigid thermoplastic hollow member is concurrently molded and fixedly attached to the support structure during formation of the rigid thermoplastic hollow member.
U.S. Pat. No. 5,354,114 discloses an integrated cross car structural duct cluster. The integrated cross car structural duct cluster of the ""114 patent is disclosed as including a steel plate that is attached to a molded plastic body of a thermoplastic or thermoset material.
In accordance with the present invention, there is provided a molded article comprising:
(a) a rigid support having a first surface, a second surface and a plurality of perforations having edges; and
(b) a molded rigid member of thermoplastic material, at least a portion of said rigid member being in abutting relationship with the first surface of said rigid support, said rigid member having a hollow interior,
wherein said article is prepared by a process comprising blow molding a thermoplastic parison precursor of said rigid member (b) onto the first surface of said rigid support (a), a portion of the thermoplastic material of said thermoplastic parison extends through at least some of said perforations of said rigid support (a), the edges of said perforations being embedded in the plastic material extending therethrough, thereby fixedly attaching said rigid member (b) to said rigid support (a).
In further accordance with the present invention, there is also provided a method of preparing a molded article comprising a molded rigid hollow thermoplastic member fixedly attached to a rigid support, said method comprising:
(I) placing said rigid support in a mold, said rigid support having a plurality of perforations having edges, a first surface and a second surface; and
(II) blow molding a thermoplastic parison precursor of said rigid hollow member against the first surface of said rigid support;
wherein a portion of the thermoplastic material of said thermoplastic parison extends through at least some of said perforations of said rigid support, the edges of said perforations being embedded in the plastic material extending therethrough, thereby attaching fixedly said rigid hollow member to said rigid support.
The features that characterize the present invention are pointed out with particularity in the claims, which are annexed to and form a part of this disclosure. These and other features of the invention, its operating advantages and the specific objects obtained by its use will be more fully understood from the following detailed description and accompanying drawings in which preferred embodiments of the invention are illustrated and described.
Unless otherwise indicated, all numbers or expressions, such as those expressing structural dimensions, quantities of ingredients, etc. used in the specification and claims are understood as modified in all instances by the term xe2x80x9cabout.xe2x80x9d